Apparatus for forming hollow plastic articles



July 5, 1960 G. v. MuMFoRD Erm.

APPARATUS FOR FORMING HOLLOW PLASTIC ARTICLES Filed Jan. 1l, 1954 7 Sheets-Sheet 1 HG. Z

650mg lf. Mrz/mona GRV/Le a. .SHERMAN July 5, 1960 G. v. MUMFORD ETAL 2,943,348

APPARATUS FOR FORMING HOLLOW PLASTIC ARTICLES Filed Jan. 11, 1954 7 Sheets-Sheet 2 G'aom M MaMFoRo GRV/1.5 8. SHERMQN /n yew 70/5 APPARATUS FOR FORMING HoLLow PLASTIC ARTICLES Filed Jan. 11. 1954 July 5, 1960 yG. v. MuMFoRD ETAL 7 Sheets-Sheet 3 5 @NW w n f mi M VJ UZ, M5. d ya wlnm.

mw\ \ml @Hw IIL APPARATUS PoR PORMING HOLLOW PLASTIC ARTICLES Filed Jan. 11, 1954 `uly 5, 1960 G. v. MUMFORD ErAL 7 Sheets-Sheet 4 July 5, 1960 G. v. MUMFORD ET AL 2,943,348

- APPARATUS FOR FQRMTNG HoLLow PLASTIC ARTICLES 65eme WMe/Fono JUIY 5, 1960 G. v. MUMFRD ETAL 2,943,348

APPARATUS FOR FORMING HOLLOW PLASTIC ARTICLES Filed Jan. 1l, 1954 7 Sheets-Shea?I 6 67E-cess L/. Afa/Fain OHV/LE 5. SHE/PMHN //7 man 70/5 52/ Cilly/g July 5, 1960 G. v. MuMFoRD ETAL 2,943,348

APPARATUS FOR FORMING HOLLOW PLASTIC ARTICLES Filed Jan. 1l, 1954 7 Sheets-Sheet 7 Q 65ans- M MoMA-opa y We@ r 2,943,348 1C@ Patented JulyY 5, 1960 Referring toiFigs. 4, 5 and 11, each df the article forming mechanisms includes an extrusion head 25 having' an 2,943,348 extrusion orifice f f r continuously providing plastic inatle.` rial in a tubular orm in a downward direction. Mo d APPARATUS FOR FORMlNGSHOLLOW PLASTIC 6 halves 26, 27 of a partible mold are positioned laterally ARTICLE on either side of the extrusion orifice. Means comprising George V. Mumford and Orville B. Sherman, Toledo, cylinders 28 individual to each mold half are provided Ohio, assigiiors to Owens-Illinois Glass Company, a for opening and closing the molds. The mold halves corporation of Ghio are constructed to form a cavity such that the upper 10 end of a length of tubing is pinched without severing Filed lan 11 1954Se1-N0 403178 and the lower end is left open in o'rder that iiuid under 13 Claims. (Cl. 18-5) pressure may be applied for expanding the tubing as s hereinafter described. Y

' Means is provided for successively severing measured This invention relates to an apparatus for forming hol- 15 lengths 0f tubing f IOIIl the t.llbil'lg being suppliedV and low plastic'articles and particularly to an apparatus for alternately transfelflng sa1 d seVefed lengths. t0` 911e Ofi 'the forming hollow plastic articles according to the method Pall 0f molds 2d; 27- This Ineans Includes Pflght memj set forth in the patent application titled, Method of bers 29,. 3ol1aV1ng vertically spaced bOrIZOnai Shafts 31, Forming Hoiiow Plastic Articles, seriai No. 381,220, 3% extending between the members A Support 33 1s liled 'September 2l, 1953 by Orville B. Sherman, now 20 Sl1dably-n10unied Online Shafts 31, 32 and ashear blade patent No 2,783,503 supporting shaft 34 pivotally mounted thereon. The shear According to the method set forth in the aforemenblade supporting shaft 34 has a Shear blade 35 mounted tioned patent application, plastic material in a suitable on one en d thefeof- The shear blade 35 1s PTOVIded With condition ol" plasticity is supplied downwardly in the WP slleaflng edges 36 and' 37 adapted t0 Pass aeIOsS the form of plastic tubing, measured lengths of tubing are 25 orloe 25a as the Shear blade SUPPOT 33 1s moved 011 successively severed from said continuously supplied tubthe Shafts 31s 32 ing and alternately transferred to a series of molds posi- AS Shown 1n Flgs- 7 and 8i a Plnlen 33 1 s fastenedi tioned laterally ofthe continuously downwardly supplied the ovfhel" end' 0f the shear blade suPPnfnng silafi 34 tubing, and e,ich tiansfoi-iod length is expanded in its and meshes with a rack 39 mounted fon limited sliding respective mold by applying fluid under pressure. 3o movement' 1n 'die support` 33 An an' eyilndel 40 1s plO- It is therefore an object of this invention to provide vloed to Cause reciprocating InOVeInent 0f besllbprt 33 an apparatus for forming hollow plastic articles accordand 1n lum the Shear biade- Shaft 49a Of the air cylining to thiS methodl der 40 is connected to the support through the rack 3 9 Other objects of the invention will appear hereinafter. (Flgg 7?- vvhen the Shear. blade snPPQt 1'las reached Basically the apparatus coninrisos moans for down 35 the limit of its movement in one direction and the a1r wardly extruding tubing of plastic materiaL'series of oyllndef 4o 1S actuated id return besllPPO a llmlted molds positioned laterally of the means for supplying the loloal movement of the rook 3 9 rolatlvo .to the Support tubing, and means for severing measured lengths of tub- 34 takes Plaoo thereby Plvoong the Shoal blade 3.5 ing from said continuously extruded tubing and tians through the pinion 38. Continued actuation of the air ferring said severed lengths to one of said molds. The 4o oyllooor thofoaftof moves the rook 39 and suPPoft 33 apparatus further includes means for applying fluid under m. moon oarl'ymg the Shear blade 35 aCIOSS the pressure to each severed length of tubing to expand said onoe 25? tnhing to tho walls of the moid In addition to the shear blade support 33, arm sup- Refoi-ring to the accomnanying drawings: ports 41, 42 are provided o'n either side of the shear pig l ls a plan View of tho apparatus, parts boing 45 blade support 33. Arms 43, 44 are mounted on the arm broken away; supports 41, 42, respectively. The movement of each Fig. 2 is a sido elovational View; arm support is limited between a position adjacent to Fig 3 is a front eleva/tional View; the oriiice and a position overlying a mold by stops 45, Fig 4 is a pian View of one of the article forming 46, respectively, mounted on a shaft 47 extending between sections of tho apparatus; the upright members. Springs 48, 49 extending between Fig. s is a view similar to Fig. 4 with the paris in the. Plghis and ,the respecta/e arm Supports 41, 42 a different position; maintain the arms 1 n position adjacent to the orifice. As Fig. 6 is a sectional View at the line VI-VI on Fig. 4; the Shear blale 35 ls moved across the orlooo Sovefrlng a Fig. 7 is a fragmentary sectional view at the line length of lubmg the severed length of tuomg 1S Pmoheo VII VH on Fig 4; 55 between the shear blade 35 and the adlacent arm 44 and Fig. 8 is a sectional View at the line VIII-VIII on commueo movement of the shear blade Pushes the arm Fig 7; and carries the severed length to a position between the Figs. 9 and 10 are sectional views through the molds mold halves' showing the expansion of the tubing; and .Each of, the molds ls provlled as.showll ln Flg 6* Fig. l1 is a sectional View at the line XI-XI on oo Wl-lh a llo-Zzlfl 50 through vihlcll fluld under pressure Fig' 4' in? bi Pimdedut" ibi, mbni mAde-r tOi-elpaislithi As shofwn in Figs. 1, 2 and 3 the apparatus comprises mg o e Wa s o 6.1m) ou Cy m er Jol" an extruder 20 for supplying plastic material to a header gltieraeg agolsliiovlded for movmg the nozzle 50 21 which in turn supplies the plastic material to a multi- 65 The Shear blade Suprlort 3 3 includes an arm 52 M phcity of article forming mechanisms 22, herein shown iooting ,downwardly and a(looted to contnot the loworr 'ond as three in number- The @K trlldr 1S dllVen by gear bOX of the severed length of tubing and guide it intoA position 23 and motor 24. The article forming mechanisms -22 as it is ,transferred to tho moli are identical in structure although they may differ in After the article has been blown and the moldhalves size for making articles of different sizes. For purare opened, a positive ejection of `the article is achieved poses of clarityronly one of the mechanisms will be described herein.

by an ,ejection mechanism 531. This mechanismv includes a stationary member 54 adapted to contact the lower end r ff v 2,943,348

of the article and a reciprocating member S slidably mounted in the stationary member. After the mold halves are opened the reciprocating member 55 is actuated by a small cylinder 56 providing a positive force on the lowerend of the article to cause it to be ejected.

The operation of the apparatus may besummarized as follows:

As shown in Fig. ll, plastic material is continuously extruded downwardly in tubular form from the orice of an extrusion head 25. As the tubing is extruded to the desired length, it is severed by movement of the shear blade 3S at an angle across the orifice 25a. This movement is accomplished by sliding of the shear blade support 33 along the shafts 3l, 32. The shearing of plastic material by movement of the angular-ly disposed blade across the orice results in a severing in such a manner that the end of the tubing being extruded remains open and the extrusion continues without substantial interruption because of the live contact of the shearing edge with the orifice. As the shear blade continues in its move# ment to the left as shown in Fig. ll (to the right as shown in Fig. 4) the upper end of the severed length of tubing is pinched between the arm 44 and the shear blade. Continued movement of the shear blade support moves the arm 44 against the action of the spring 49. The severed length of tubing is thereby carried to a position between the halves of the mold (Fig. 5 The mold halves are then closed by actuation of the cylinders 28, pinching the upper end of the tubing and leaving the lower end of the tubing open. The nozzle 50 is then brought into contact with the lower end of the tubing by actuation of the cylinder 51 and iluid under pressure is introduced to expand the plastic material to the confines of the mold. After the article has been formed the molds are opened and simultaneously the lower end of the hollow article which has been formed is given a slight movement by actuation of the ejection mechanism 53 to cause a positive ejection of the article.

After the length of tubing has been transferred to the mold for expansion, the shear blade may be returned and a second length of tubing may be severed from the extruder. This is accomplished by reversing Ithe action of the cylinder 40. Initial reversal of the cylinder 40 causes movement of the shaft 40a pivoting the shear blade through the rack 39 and pinion 3S (Fig. 7). Further movement of the shaft 40a moves the shear blade through the shear blade support 33 toward the orice. The arm support 42 and arm 44 are carried along with the movement of the shear blade support through the action of the spring 49.

As the shear blade is moved past the orifice, a second length of tubing is severed and pinched between the second arm 43, and thereafter transferred between the halves of the second mold. The pinching or gripping action between the shear blade and the arm 43 is insured by the spring 48 against which the arm must be moved. After the tubing has been transferred, the second mold may be closed and the tubing expanded to the walls of the mold in a similar manner as in the iirst length of tubing. The movement of the shear blade may then be reversed initially pivoting the shear blade and thereafter moving the shear blade across the oriiice again to sever a third length of tubing and again begin the cycle of operations.

The terms tubular or tubing are used herein to dene any hollow shapes of plastic material and include noncircular and irregular shapes.

The terms plastic and thermoplastic are used herein to dene any organic material capable of being provided in a condition of plasticity for expansion to hollow form.

Modilications may be resorted to within the spirit and scope of the appended claims.

We claim:

1. An apparatus for forming hollow plastic articles comprising an extrusion device having an extrusion orice for downwardly extruding plastic material in the Iform of a tube, a pair of partible molds, one of said molds being positioned laterally on each side of said orifice, means individual to each said mold for opening and closing said mold, a shear blade mounted for lateral movement across said orice in such a manner that a length of tubing is severed from the tubing being extruded and the end of the tubing being extruded remains open, means for moving said shear blade from a position overlying one mold across said orice to a position overlying the second mold, means cooperating with said shear blade for gripping and transferring a severed length of tubing from a position below the orifice to one of the two molds, and means individual to each said mold for supplying uid under pressure to the tubing to expand the tubing to the walls of the mold.

2. The apparatus set forth in claim 1, said molds being constructed in such a manner that one end of the severed length of tubing is pinched and `the other end of the severed length of tubing is left open.

3. The apparatus set forth in claim l, said means cooperating with the blade to grip and transfer the severed lengths comprising a pair of arms, said arms being mounted for movement along the path of the shear blade, one of said arms being mounted on either side of said shear blade, means for resiliently holding each said arm in position adjacent the orifice whereby when the shear blade is moved across the orice, severing a length of tubing, continued movement of the shear blade pinches the severed length between the shear blade and the arm and further movement causes the arm to move carrying the pinched length of tubing to a position between the parts of the partible mold, and means for supplying uid under pressure to the tubing when the parts of the mold are closed to expand the tubing to the walls of the mold.

4. An apparatus for forming hollow plastic articles comprising an extrusion device having an extrusion orifice for downwardly extruding plastic material in the form of a tube, a pair of partible molds. one of said molds being positioned laterally on either side of said orifice, a shear blade having a pair of shearing edges movable across and in contact with said orifice and severing lengths of tubing from the tubing being extruded in such a manner that the end of the tubing being extruded remains open, a support in which said shear blade is pivotally mounted, means for moving said support in such a manner that the shear blade is moved from a position overlying one mold across said orifice to a position overlying the second mold, means for pivoting the position of the blade with respect to the support thereby bringing alternate shearing edges of the blade into contact with the orifice during alternate directions of movement of the support, an arm mounted for limited movement between one mold and a position adjacent said orilice, a second arm mounted for limited movement between said second mold and a position adjacent said orifice, means individual to each said arm for resiliently holding said arm in position adjacent the orifice, whereby movement of the shear blade across the orifice severs a length of tubing and continued movement of the shear blade causes said severed length of tubing to be gripped between the shear blade and the arm adjacent the orifice and further movement of the shear blade causes the arm to move, transferring the severed length of tubing to a position between the parts of the mold on one side of the orifice, whereby upon return movement of the shear blade the shear blade is pivoted bringing the second shearing edge of the shear blade into position to contact with the orifice, severing a second length of tubing and causing said second length of tubing to be gripped between the shear blade and the second arm and be thereby transferred to a position between the parts of the second mold, and means individual to each said mold for supplying fluid under pressure to a length of tubing supplied thereto to expand said tubing to the walls of the mold.

5. The apparatus set forth in claim 4, said means for pivoting the shear blade with respect to its support comprising a rack mounted for limited sliding movement in said support, one end of said rack being connected to the means for moving the support, a pinion meshing with the said rack and connected to said shear blade whereby upon movement of the means for moving the support the rack is caused to move a limited distance relative to the support pivoting the shear blade and upon further movement of the means for moving the support, the support and Ain turn the shear blade are moved in unison.

6. The apparatus set forth in claim 4 including means for guiding the lower end of the severed length of tubing during its transfer to a position between the parts of a mold.

7. The apparatus set forth in claim 6, said guiding means including an arm mounted on said support and adapted to contact the lower end of the tubing.

8. The apparatus set forth in claim 4 including means for causing a positive ejection of the plastic articles from the molds after the tubing has been expanded to the walls of the mold and the mold parts are open.

9. The apparatus set forth in claim 8, said means comprising a reciprocating plunger adapted to strike the lower part of the article when the mold halves are opened, and means for reciprocating said plunger.

l0. An apparatus for forming hollow plastic articles which comprises means for continuously supplying tubing of plastic material, said tubing being in a condition of plasticity to permit expansion and setting in predetermined form, means for severing a length of tubing from the remaining tubing being supplied in such a manner that the end of the tubing being supplied remains open and the extrusion movement of the tube being supplied remains substantially undisturbed, said severing device being mounted for movement laterally from the tube supplying means alternately to a plurality of molding positions, means cooperating with and movable by the severing device for gripping and transferring said severed lengths of tubing from the tube supplying device to the various positions, means to move said severing device alternately between said forming positions, and means at each said molding position adapted to expand said tube lengths to hollow articles.

11. An apparatus for forming hollow plastic articles which comprises means for continuously supplying tubing of plastic material, said tubing being in a condition of plasticity to permit expansion and setting in predetermined form, means for successively severing lengths of tubing from the remaining tubing being supplied in such a manner that the end of the tubing being supplied remains open and the movement of the tube being supplied remains substantially undisturbed, said severing device being mounted for movement between the tube supplying device and alternate positions spaced laterally of said tube supplying device, and a pair of gripping devices adapted to individually cooperate with said severing device for gripping and transferring the severed lengths of tubing to the respective positions, one of said gripping devices being mounted for limited movement between the tube supplying device and the one lateral position and the other gripping device being mounted for limited movement between the tube supplying device and the second lateral position.

l2. In an apparatus for forming hollow plastic articles having an opening at one end including an extrusion device for extruding heated plastic material downwardly from an oriice in the form of an unconined hollow open-ended tube, a shear blade mounted exteriorly of said orice for lateral movement to sever a length of extruded tubing therefrom, said severance leaving successive extrusions of tubing with open ends, and means to actuate said shear blade, the improvement of a partible mold at a molding station remote from the orifice and arranged for opening and closing movement, said mold having an open end portion and a body forming portion, transfer means engageable with a severed tube at the orifice and operable to transfer the severed tube to the molding station, means for closing said mold on said tube at said molding station with an open end portion of said tube confined `in the open end portion of said mold, a combination positioning and blowing nozzle insertable into the open end of said tube after closure of the mold and cooperating with the mold to secure said tube in axial alignment with the cavity of said mold, and means to supply fluid runder pressure through said nozzle to expand said tube in said mold.

13. 'In an apparatus for forming hollow plastic articles comprising an extrusion device for extruding heated plastic material downwardly from an lorice in the form of an unconined hollow open-ended tube, a pautible mold at a molding position spaced from said orifice and arranged for opening and closing movements, said mold having its neck and body forming portions in inverted order, a shear blade mounted between said orice and mold and arranged for lateral movement across said orifice to sever la length of extruded tubing therefrom, said severance leaving the successive extrusions of tubing with open ends, means to actuate said shear blade, vertically spaced aligning means contactable with the free ends of the severed tube and operable to maintain the lower free end of the tube in vertical alignment with the upper portion of said extruded tube, means guiding movement of said aligning means and said tube to the molding position, means actuating said partible molds intermediate said spaced aligning means to enclose said aligned tube with the open end thereof in the neck portion of said mold, a combination shaping and blowing nozzle insertable in the lower open end of said tube and arranged to position said tube in axial alignment with the cavity of said mold, and means to supply fluid under pressure through said nozzle to expand said tube in said mold;

References Cited in the tile of this patent UNITED STATES PATENTS 2,262,612 Kopitke Nov. 11, 1941 2,288,454 Hobson June 30, 1942 2,562,523 Brunet July 31, 1951 2,597,558 Bailey May 20, 1952 2,657,431 Slaughter Nov. 3, 1953 2,715,751l Weber Ang. 23, 1955 2,783,503 Sherman Mar. 5, 1957 2,810,934 Bailey Oct. 29, 1957 

